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China Communications 2007年第3期4卷 63-68页

作者： Nikos J.Farsaris peter P.stavroulakis Aristotle's University of Thessaloniki Faculty of Electrical Engineering Telecommunications Department Technical University of Crete Electronic and Computer Engineering Department Systems Sector Prof.

Tropospheric Scattering(Troposcatter) and Tropospheric Ducting are two different mechanisms due to in-homogenoueties in the lower part of the Earths *** common influence in propagation of microwaves is studied here in order to achieve a feasible naval communication *** not new,Troposcatter together with Tropospheric Ducting communications are regaining popularity in current military and civil applications such as isolated islands and oil extraction facilities in the open *** innovation proposed here is the application of such systems in naval communications where at least one of the stations is *** propagation together with fading models are simulated using appropriate programs and scientific simulation packets in order to predict maximum range of such communication systems in each dominant mode of *** appropriate antenna design proposals are given to overcome the high propagation loss and minimize possible interferences.

关键词： naval communications tropospheric scattering tropospheric ducting

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Editor's Note

China Communications 2007年第1期4卷 4-7页

作者： peter stavroulakis Technical University of Crete Greece

It is with great pleasure that I am serving as a Guest Editor for special issues of the CHINA COMMUNICATIONS JOURNAL on Communications and Information Security in *** June,2007. The goal of these issues is to present ... 详细信息

关键词：护面

Customized Biometric Architecture for Access Control in Stadiums based on Federated Identities

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China Communications 2007年第3期4卷 54-62页

作者： Christos K.Dimitriadis peter stavroulakis D.Polemi University of Piraeus 80 A.Dimitriou 18534 PiraeusGreece

This paper,resents a system called Athlos2,which implements strong access control for athletic events, enhancing the safety feeling of event spectators. Athlos2 integrates intelligent biometric access control systems and smart cards,under a protocol that complies ith the specification of the Liberty Alliance project for federated identities.A pilot version of Athlos2 was deployed and tested in terms of acceptability,information security and performance.

关键词： physical access control security biometrics ahletic events

On the QoS Assessment of Video Sessions in Heterogeneous 3G-WLAN Networks with Seamless and Secure Mobility Support

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China Communications 2007年第1期4卷 105-119页

作者： Ilias Politis Michail Tsagkaropoulos Stavros Kotsopoulos Tasos Dagiuklas peter stavroulakis Dept.of Electrical and Computer Engineering University of Patras26500 Greece Dept.of Telecommunications and Network Systems Technical Institute of MessolonghiNafpaktosGreece Technical University of Crete Roumeliotaki 17 str.73100 LentarianaChaniaCreteGreece

Real-time video data transmission is currently emerging as a popular application among mobile users but it is very sensitive to QoS degradation due to packet losses in wireless *** order to achieve service continuity and integrity upon handoffs among heterogeneous networks,provisioning of seamless and secure mobility is ***,in order to reduce the delay and packet losses during vertical handovers we need to employ supportive protocols like context *** this paper we evaluate the QoS of video transmission over a heterogeneous 3G-WLAN *** aggregate video data traffic is represented by a dynamic two-dimensional Markov chain model,which has been evaluated against real video data *** the vertical handover, appropriate AAA handshaking and enhanced mobility management using context transfer have been *** QoS evaluation of video streams was performed based on peak signal-noise ratio(PSNR) measurements,while we analyticallyestimated the number of packet losses during *** results show that both packet loss within the converged network and loss occurrence affecting the perceived video quality is reduced. Moreover,the proposed context transfer scheme minimizes handover delay and the number of lost packet up to 3 times compared to standard AAA handshaking.

关键词： heterogeneous wireless networks multiplexed video traffic RADIUS-AAA,context transfer

Secure Packet Video Transmission over Wireless Multimedia Sensor Networks

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China Communications 2008年第2期5卷 59-67页

作者： Ilias Politis Michail Tsagkaropoulos Sofia Gouskou Stavros Kotsopoulos peter stavroulakis Dept.of Electrical and Computer Engineering University of Patras Ericsson Research Technical University of Crete

This paper proposes a packet scheduling scheme thatoptimizing the coded video transmission overmultipath wireless multimedia sensor networks interms of received video distortion and power efficiencyenhances the security aspects of the *** the aggregate transmission rateavailable at the network cannot support the requiredtransmission rate,the scheduling algorithm can selectivelydrop combinations of video packets prior totransmission to adapt the rate of the sender to thelimitations of the wireless channel *** algorithms are *** Baselinescheme utilizes a novel distortion prediction modeland decides upon which packet can be dropped priorto transmission based on the packet’s impact on thevideo *** addition to the bandwidthlimitations,the Power aware packet scheduling is an extension of the Baseline capable of estimating thepower that will be consumed by each node during thetransmission;hence it can control the power consumptionby selectively drop packets of low importanceto the decoded *** results indicatethe efficiency of the proposed scheduling schemein terms of received video distortion(PSNR)andpower consumption.

关键词： Terms-WMSN packet scheduling power consumption video distortion

Applications of Statistical Signal Processing in Image Data Compression

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Applications of Statistical Signal Processing in Image Data ...